I am troubleshooting why my washer fluid indicator light (IL) stays on in my car even though the fluid level sensor is disconnected. The IL stays on after the car is started. Also the Central Warning Lamp (CWL) and Acknowledgment Button Lamp (ABL) also stay illuminated after the initial pre start bulb check. If I press the Acknowledgment Button, then the ABL and the CWL go out but the IL stays lit. This is consistent behavior for low fluid.

My understanding of how the system works, positive voltage is applied to the from the CE to the IL and it is grounded through the bulb control module for bulb testing -AND/OR- grounded through the float switch and then to the ground point at the CE. Subsequently if I disconnect the float switch the ground is interrupted after the the bulb test phase and the IL should not light.

But is stays on, so why... is the bulbs control module faulty? Could it be that I have also unplugged my intensive washer and headlight washer pumps? I would not think that is the case.



[edit] A random thought.... I recently converted the dash the LED if that could be a contributor. Could the LED causing problems in the circuit? Could it be in backward polarity and than be causing the issue?

As always, your trouble shooting help is appreciated...

Mike
1988 S4

 

did the fault happen after you plugged the pod into the car after swapping in the LEDs

 

Yes, this problem arose after I installed LED bulb in the gauge cluster. So that tells me that the problem is associated with the LED (unlikely) or the problem pre-existed and the old bulb was burnt out (more likely).

 

I did some more research this morning and compiled the information in the WSM and wiring diagrams (see below) to help illustrate how the system is wired. The IL bulb has constant + voltage and is illuminated when a ground contact is made via the float switch. I have disconnected the switch and thus there is no ground and the IL should not be lit. According to the WSM, if the CWL, ABL, and IL are lit but their is no error, I should test the central warning unit:
So this is where I am stuck. I don't understand how to test the module? Help appreciated.

 

Update, I was able to trace the issue down to the faulty float sensor, I must have broke it when I removed it and was cleaning the rust out of the washer tank. I feel a little silly for not testing before reinstalling. Thanks for your help.